1. Black Holes

2. Objectives By the end of this presentation you will be able to:
Explain What a Black Hole Is
Explain how Black Holes Form
Describe the Different Types of Black Holes
Describe the Structure of a Black Hole
List Some of the Properties of Black Holes
Describe the Behavior of Black Holes

3. 1. What Are Black Holes? Definition
a celestial body so dense that light or other electromagnetic radiation cannot escape its gravitational pull
a region where matter collapses to infinite density, and where, as a result, the curvature of space-time is extreme

4. 1. (cont.) Curvature of Space-Time

5. 2. How Do Black Holes Form?
Enormous gravitational pull is necessary to create a black hole - caused by a star collapsing.
When a star’s core has been burned up entirely, the rest of the star will pull into the empty space and create a new core. If that material will not burn, the star is dead.
If the core continues to compress into itself, and if it has enough mass, the star will become a black hole.

6. 3. Types of Black Holes Two Types:
Schwarzschild - Non-rotating black hole
Kerr - Rotating black hole

7. 3. (cont.) Types of Black Holes
1. Schwarzschild
2. Kerr

8. 4. Structure of Black Holes
Schwarzschild: simplest black hole; core does not rotate.
Singularity - The collapsed core
Event horizon - The opening of the hole
Kerr:
Ergosphere - An egg-shaped region of distorted space around the event horizon (The distortion is caused by the spinning of the black hole, which "drags" the space around it.)
Static limit - The boundary between the ergosphere and normal space

9. 5. Properties of Black Holes
Three properties that can or could be measured:
Mass
Electric charge
Rate of rotation (angular momentum)

10. 6. How Do Black Holes Behave?
Can create jets of gas
May create gamma ray bursts
Can evaporate

11. 7. Summary Black holes are incredibly dense They curve space-time
Not even light can escape
They form from massive star collapse
2 types = Schwarzchild & Kerr
Structure = singularity + event horizon
They have mass, electric charge, and rotation rates
They can create jets of gas, gamma ray bursts, and evaporate